Selective well treating and gravel packing apparatus

ABSTRACT

The apparatus and method provides the ability to selectively treat a producing zone in a well and to gravel pack an annulus in the well casing outside a screen type liner pipe. A tubing string extending from the surface of the well bore is connected to a packer by a crossover valve. Flow down the tubing string is directed to an annulus below the packer, then inwardly through the screen type liner, then upward through the crossover into the annulus above the packer and then to the earth&#39;&#39;s surface. Communication from the crossover to the annulus above the packer may be selectively closed to permit a treating pressure to be exerted down the tubing to force a treating fluid into the producing zone. The treating pressure is isolated from the casing above the packer to protect the casing above the packer.

[ Dec. 16, 1975 SELECTIVE WELL TREATING AND GRAVEL PACKING APPARATUSFarley 166/226 Young et all .7 166/226 [75] Inventors: g g i i g gPrimary Examiner-William R. Cline 0 E orace Assistant Examiner-H. JaySpiegel l bert retna Attorney, Agent, or Firm-William E. Johnson, Jr.;[73] Assignee: Dresser Industries, Inc., Dallas, Tex. Michael J Caddell[22] F1led: Mar. 18, 1974 ABSTRACT [21] PP N04 452,234 The apparatus andmethod provides the ability to se- Related Application Data lectivelytreat a producing zone in a well and to gravel [62] Division of Ser No194 228 Nov 1 1971 Pat No pack an annulus 1n the well cas1ng outslde ascreen 3,818,986 type liner pipe. A tubing string extending from thesurface of the well bore is connected to a packer by a [52] us CL251/344, 166/226. 251/340. crossover valve. Flow down the tubing stringis di- 251/346 rected to an annulus below the packer, then inwardly 511m. 01. F16K 31/44 through the Screen type liner upward through [58]Field of Search 166/226 251/340 the crossover into the annulus above thepacker and 251/341 345 6 then to the earths surface. Communication fromthe l i crossover to the annulus above the packer may be se- [56]References Cited lectively closed to permit a treating pressure to beexerted down the tubing to force a treating fluid into the UNITED STATESl )ATENTS producing zone. The treating pressure is isolated fromgamtmerstem iii the casing above the packer to protect the casing un3,094,306 6/1963 Conrad 251/344 above the packer 3,106,379 10/1963Sciuto et al 251 344 4 Claims, 8 Drawing Figures US. Patent Dec. 16,1975 Sheet 1 of 6 H I II II I! II II I [I\|l II VII) US. Patent Dec. 16,1975 Sheet 2 of 6 FIG. 3

US. Patent Dec. 16, 1975 t v// /////77777777/71 @P/ Sheet 3 of 6 FIG. 4

US. Patent Dec.16,1975 Sheet4of6 3,926,409

1 n /uo US. Patent Dec. 16, 1975 SheetS 0f6 US. Patent Dec. 16, 1975Sheet60f6 3,926,409

FIC17 SELECTIVE WELL TREATING AND GRAVEL PACKING APPARATUS This is adivision of application Ser. No. 194,228, now US. Pat. No. 3,818,986,filed Nov. 1, 1971, for Selective Well Treating and Gravel PackingApparatus.

BACKGROUND OF THE INVENTION The field of the invention relates totreating and gravel packing oil and gas and other types of wells. Someproducing wells contain producing zones that have loose sand. Flow ofthe desired liquid or gas from such zones into the well bore oftencarries undesirable amounts of sand which can cause erosion of theequipment and can cause plugging of the flow passages. It has been foundthat provision of a screen pipe within the perforated producing zonewith suitable small size holes or slots provided in the screen pipe andhaving the annulus between the screen pipe and the casing filled with asuitable size grave] of a predetermined screen size allows passage ofthe desired fluids from the producing zone and prevents passage of thesand. Producing zones also sometimes require treatment in order toincrease the area of flow passages to the well bore to permit greaterdrainage of the producing zone into the well bore. It is sometimesdesired to treat a producing zone with acid or another fluid to increasethe productivity of the zone.

The prior art includes crossover arrangements whereby gravel can bepumped into an annulus between a screen pipe and the casing by providinga crossover flow arrangement communicating a tubing string to an annulusbelow a packer outside a screen pipe and providing a return passagethrough the packer communicating with the annulus outside the tubingabove the packer. The prior art in treating producing zones with acid orother fluids includes a simple or heavy duty packer connected to atubing string allowing the treating fluid to be pumped to an areaadjacent the producing zone, allowing displaced fluid to return aroundan unset packer or through an open valve in the tubing string providingcommunication between the tubing and the casing above the packer.However, it has heretofore been unknown in the art to provide a singleapparatus selectively capable of performing both functions.

It is therefore an object of this invention to provide an apparatus forselectively treating and gravel packing a well.

It is a further object of this invention to provide apparatus and methodfor gravel packing and treating a well without removing the tubingbetween the treating and gravel packing operations.

It is a still further object of this invention to provide apparatus andmethod for acidizing and gravel packing a producing zone in a well.

It is a still further object of this invention to provide completelyretrievable apparatus for treating and gravel packing a producing zonein a well.

It is a still further object of this invention to provide a selectivelyoperable apparatus for treating and gravel packing a well withoutimposing the pressure required for treating the zone on the casing abovethe packer.

SUMMARY OF THE INVENTION These and other objects of the invention areachieved by methods and apparatus for use in a Well casing in a wellbore including a packer anchored in the well casing and a tubing stringextending from the surface of the well bore through the packer, whereinan upper portion of the tubing forms an upper annulus and a lowerportion of the tubing below the packer forms a lower annulus, includinga screen pipe connected to and communicating the lower tubing stringportion to the lower annulus, and a crossover valve arrangement forcommunicating the upper tubing string portion to the lower annulus andfor selectively communicating the lower tubing string portion to theupper annulus and for selectively preventing communication between thelower tubing string portion and the upper annulus.

DESCRIPTION OF THE DRAWING FIG. 1 is a schematic illustration, partiallyin elevation and partially in section, showing an apparatus according tothis invention.

FIG. 2 is an enlarged view of a portion of the apparatus as illustratedin FIG. 1.

FIG. 3 is an elevation showing the jay-slot on the mandrel of FIG. 2.

FIG. 4 is a view, partially in elevation and partially in section, ofthe crossover valve of FIG. 2 shown in the closed position.

FIG. 5 is a schematic view, partially in elevation and partially insection, illustrating an alternate embodi ment according to thisinvention.

FIGS. 6A and 6B comprise a schematic view of a well completion withstill another alternate embodiment according to this invention.

FIG. 7 shows an enlarged portion of the apparatus of FIG. 6 with someparts operably repositioned.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, a well boreis illustrated with a well casing 10 in place. A packer 12 having a sealbore 14 is anchored in sealing engagement with the casing 10. A tubingstring 18 extends from the surface of the well bore and is in engagementwith a crossover valve assembly shown generally at 20. A seal nipple 16is located in sealing engagement with sea] bore 14 by shoulder 81. Thecrossover valve 20, the shoulder 81, a seal nipple 16 and a lowerportion 44 of tubing string 18, a seal nipple 58 and a collet arethreadedly connected into an assembly. The crossover valve assembly hasa housing 22 connected to the tubing string 18. A mandrel 24 is disposedin a rotatable and slidable relation to the housing 22. The axialmovement and rotation of the housing 22 on mandrel 24 is controlled by ajay-pin 26 threadedly engaged to housing 22 and cooperating withjay-slot 28 formed in the outside of mandrel 24. The crossover valve isillustrated in the open position communicating a port 30 in the housingwith passage 36 in the mandrel. A crossover 34 is disposed in sealingengagement with mandrel 24 and having passages 36 and 38 communicatingwith port 30. An inner tubing string 40 is connected with passage 38 incrossover 34 and extends to a barrier 42 in a lower portion 44 of tubingstring 18. A suitable seal 46 seals the lower end of tubing string 40 toa lower portion 44 of the tubing string 18. A tubular extension ortubing string 48 is attached to the barrier 42 to extend the passagewayin tubing string 40, the lower end of tubing string 48 having a bottomopening 49 to allow fluid communication between screen pipe 74 and thetubing string 48. The lower portion 44 of tubing string 18 has at leastone port 50 above the barrier 42. A tubing string 52 is suspended belowpacker 12. At least one port 54 in the tubing string 52 is incommunication with the ports 50 in the tubing string lower portion 44. Aseal bore 56 is provided inside the tubing string 52. The seal nipple orseal assembly 58 is provided in sealing engagement with the seal bore56. The collet 60 is a tubular member with axial slots 62 and isprovided with an enlarged portion engaging a groove 64 in the tubingstring 52. The collet 60 is a heat treated spring member which isdeformable to expand into engagement with the groove 64 and deformableto a smaller diameter upon upward axial thrust to engage groove 66. Thetubing string 18 may be located at a position upward from that shown inFIG. 1 so that the collet 60 can engage a groove 66 which is positionedto locate the seal nipple 16 above the seal bore 14 in the packer 12.The casing is provided with a multiplicity of perforations 70 tocommunicate with a producing zone 72 to allow oil and/or gas productionto flow into the casing 10. The tubing string 52 is provided with ascreen pipe 74 which has a multiplicity of small holes or slots 76. Alower annulus 78 is formed between the casing 10, the tubing string 52and the screen pipe 74.

This apparatus provides the ability to place into the lower annulus 78particles of rock called gravel 80 which is of a selected screen sizelarge enough to be retained by holes or slots 76 and to allow passage ofthe oil and gas from producing zone 72 through perforations 70 and slots76 but prevent the flow of sand from the producing Zone 72. The shoulder81 is connected to the mandrel 24 to locate the seal nipple 16 in sealbore 14 and to position tubing string 18 in proper place in the wellbore.

Referring now to FIG. 2, the tubing string 18 is illustrated connectedto a threaded adapter 19 which is threadedly engaged to housing 22.Housing 22 has an upper seal bore a. A seal ring 20b which may be of theO-ring type is positioned in sealing engagement between the mandrel 24and seal bore 20a. A second seal 23 is molded and bonded into a metalsleeve which is sealed to mandrel 24 by seal 250 which may be of theO-ring type. A retaining ring 25b holds the seal 23, sleeve 25 and seal25a in place. At least one port is provided in the wall of housing 22. Asea] bore 27 is provided in the lower end of housing 22. At least oneseal 29 and preferably two seals 29 as illustrated are provided insealing engagement with seal bore 27 and a sleeve 31 which is inencircling relationship with mandrel 24. A seal 31a which may be of theO-ring type seals between mandrel 24 and sleeve 31. Sleeve 31 is held inposition on mandrel 24 by retaining ring 33 positioned in a groove onmandrel 24 and by coupling 35 which is threadedly engaged to mandrel 24.

In the position of the crossover valve shown in FIG. 2, port 30 inhousing 22 is in communication with passage 36 and crossover 34. Passage38 in crossover 34 provides communication to tubing string 40 which isthreadedly engaged with the lower portion of crossover 34. Crossover 34forms an integral portion of mandrel 24 and leaves a passageway 37through mandrel 24 which provides communication from tubing string 18above crossover valve 20 with the annular passage 39 formed between thelower portion 44 of tubing string 18 which is threadedly engaged withcoupling 35 and between tubing string 40.

Relative movement of mandrel 24 within housing 22 is controlled byjay-pin 26 which is threadedly engaged 4 in the wall of housing 22 andis movable in jay-slot 28 to lock the mandrel and housing in one axialposition and allow movement to another axial position as hereinafterdescribed.

FIG. 3 is an exterior view of the mandrel 24 showing the jay-slot 28 andO-ring seal 20b. Jay-pin 26 is illustrated in position 26a as shown inFIG. 2. The valve 20 may be held in the open position shown while thejaypin is in the position illustrated by circle 26a and by circle 26band positions intermediate 26a and 26b. By moving jay-pin to position26a and then simultaneously rotating the housing 22 and axially movingthe housing 22 upward on the mandrel 24, the jay-pin may be movedupwardly and to the right as shown in FIG. 3 and moved through anangular portion 28a of jay-slot 28 and upon continued axial movement maybe moved relative to mandrel 24 until the jay-pin 26 is in position 26cto move the crossover valve assembly 20 to the closed position shown inFIG. 4.

Referring now to FIG. 4, the axial movement lifting the tubing strong 18upwardly to position the jay-pin 26 in position 26c as illustrated inFIG. 3 will move the housing 22 upwardly to position seal 23, and seals29 in sealing engagement with seal bore 27. Since the passage 36 islocated intermediate seals 23 and 29, communication from passage 36 toport 30 is prevented while the valve is in the extended positionillustrated in FIG. 4.

OPERATION OF THE PREFERRED EMBODIMENT The packer 12 is anchored, inaccordance with various methods well known in the art, in sealingengagement with the casing 10 at the desired proper depth, suspendingthe tubing string 52 so that screen pipe 74 has the slots or holes 76 atapproximately the same depth as the perforations in the casing 10. Thetubing 48, the lower portion of the tubing 44 and the barrier 42 and theseal nipple 16, the locator 81, the crossover valve 20 and the tubingstring 40 are all lowered into position on tubing string 18. The sealnipple 16 is positioned in sealing engagement with seal bore 14 inpacker 12. The crossover valve 20 is lowered into the well in the openposition with ports 30 in communication with passage 36, passage 38 andtubing string 40.

In treating the producing zone with acid, the desired amount of acid ispumped into the tubing string followed by a suffficient quantity ofwater, mud or other fluid to position the acid in proximity to theproducing zone 72. Flow is established down inside the tubing string 18,down through passage 37 (in FIG. 2) in valve 20, down through annularpassage 39, and out through ports 50 and 54 into the lower annulus 78into proximity with zone 72. The already existing well bore fluid, aheadof the acid or the treating fluid, is displaced ahead of the acid andenters the slots 76 in the screen pipe 74 and flows into the bottomopening 49 of tubing string 48 and up through tubing string 40 throughpas sages 38 and 36 and port 30 into the upper annulus in the casing 10external of the tubing 18 above the packer 12 where such fluid isconducted to the surface of the well bore. When the acid or othertreating fluid is positioned in proximity to the producing zone, byknown methods such as counting pump strokes, the tubing string 18 islowered so that the jay-pin 26 moves to position 26a in the jay-slot 28as illustrated in FIG. 3. Then a slight left-hand rotation of the tubing18 while picking up the tubing string will move the jay-pin 26 toposition 26c and close the crossover valve 20 as illustrated in FIG. 4.Pressure is then applied down the tubing string 18 to force the treatingfluid, for example, acid, into the producing zone 72. The pressurerequired to force the fluid into the producing zone is imposed throughthe slots 76 in the screen pipe 74 and into the tubing string 48, thetubing string 40, the passage 38 and the passage 36. Communication tothe annulus above the packer is prevented by the seals 23 and 29 inengagement with the seal bore 27 in the valve.

It is desirable to avoid imposing a treating pressure on a casing stringabove the producing zone because the casing commonly has less pressurecapability than a tubing string. Also since the casing is permanentlyinstalled in the well, erosion and corrosion may significantly reducethe pressure capability of the casing during the life of the well.Therefore, a casing string might rupture if a treating pressure wereimposed against the inside of the casing.

Once the treating fluid has been pumped into the producing zone, thecrossover valve may be opened by lowering tubing string 18 to itslowermost position in the well casing positioning jay-pin 26 in position26a or 26b as illustrated in FIG. 3. The angular portion of jay-slot 28will guide jay-pin 26 from position 260 to position 26a upon axialmovement of the housing 22 on the mandrel 24. Communication is thenestablished between the crossover passage 38, passage 36 and housingport 30 communicating the producing zone with the annulus above thepacker. A mixture of gravel and fluid such as water may then be pumpeddown the tubing. The mixture will flow down through passage 37, throughannular passage 39 and out the ports 50 and 54 into the lower annulus 78outside the tubing string 52 below the packer. The fluid will passthrough slots 76 in the screen pipe but the gravel will be of apredetermined size large enough that the gravel particles will not passthrough the screen pipe and the gravel will be deposited in the annulusbetween screen pipe 74 and casing adjacent the producing zone. The fluidwith which the gravel was pumped into position will pass on throughslots 76 in the screen pipe and up through the tubing string 48 and thetubing string 40 through the passages 38 and 36 through the port 30 intothe upper annulus where fluid is returned to the surface of the wellbore.

As an optional feature of the invention, after the gravel is placed, thetubing may be lifted to disengage the seal nipple 16 from the seal bore14 and be lifted sufficiently to engage the collet 60 with groove 66with valve in the open position. Fluid may then be pumped down thecasing annulus to pass down through seal bore 14 down through theannulus between the lower portion 44 of the tubing string and the tubingstring 52 and pass into the tubing string 44 through the port 50 whereflow can proceed upward through passage 37 and upward to the surface ofthe well through tubing string 18. Debris in the upper annulus of thecasing and on top of packer 12 may thereby be entrained by the fluid anddisplaced upwardly through the tubing string 18 to the surface of thewell bore.

DESCRIPTION OF THE ALTERNATE EMBODIMENTS Referring to FIG. 5, a wellbore is illustrated with a well casing 110 intersecting a producing zone172. A packer 112 having a seal bore 114 is anchored in sealingengagement with the casing 110. A tubing string 118 extends from thesurface of the well bore and is in engagement with a crossover valveassembly shown generally at 120. A seal nipple 116 is located in sealingengagement with seal bore 114 by a shoulder 181. The crossover valve120, the shoulder 181, a seal nipple 116 and a lower portion 144 oftubing string 118, a seal nipple 158 and a collet 160 are threadedlyconnected into an assembly. The crossover valve assembly has a housing122 connected to the tubing string 118. A mandrel 124 is disposed in arotatable and slidable relation to the housing 122. The axial movementand rotation of the housing 122 on mandrel 124 is controlled by ajay-pin 126 threadedly engaged to housing 122 and cooperating withjay-slot 128 formed in the outside of mandrel 124. The crossover valveis illustrated in the open position communicating a port 130 in thehousing with port 136 in the mandrel.

In the position shown in FIG. 5, housing ports 130 are in communicationwith ports 136 in the wall of mandrel 124. A barrier 142 is positionedin sealing engagement in mandrel 124 above mandrel ports 136. An innertubing string is sealingly engaged to barrier 142. Tubing string 144extends below crossover valve 120. The shoulder 181 is provided on thelower tubing string 144 to locate the tubing with respect to the packer112 and to locate seal nipple or seal assembly 116 in seal bore 114 inpacker 112. Crossover 134 is positioned inside lower string 144 andprovides a port 136 which communicates with port 154 in lower tubingstring 152 which is suspended below packer 112. Tubing string 140extends to and seals in crossover 134 and communicates with passage 138in crossover 134. An inner tubing string 140 is connected with passage138 in crossover 134 and extends to a barrier 142 in the mandrel 124. Atubular extension 148 may be attached to a barrier 149 to extendcommunication to the passageway 137. The lower portion 144 of tubingstring 118 has at least one passage 150 in the crossover 134. A tubingstring 152 is suspended below packer 112. At least one port 154 intubing string 152 is in communication with the passage 150. A seal bore156 is provided inside the tubing string 152. The seal nipple or sealassembly 158 is provided in sealing engagement with the seal bore 156.The collet 160 is a tubular member with axial slots 162 and is providedwith an enlarged portion engaging a groove 164 in the tubing string 152.The collet 160 is a heat treated spring member which is deformable toexpand into engagement with the groove 164 and deformable to a smallerdiameter upon upward axial thrust to engage groove 166. The tubingstring 118 may be located at a position upward from that shown in FIG. 1so that the collet 160 can engage a groove 166 which is positioned tolocate the seal nipple 116 above the seal bore 114 in the packer 112.The casing 110 is provided with a multiplicity of perforations 170 tocommunicate with the producing zone 172 to allow oil and/or gasproduction to flow into the casing 1 10. The tubing string 152 isprovided with a screen pipe 174 which has a multiplicity of small holesor slots 176. A lower annulus 178 is formed between the casing 110, andthe tubing string 152 and the screen pipe 174.

This apparatus provides the ability to place into the lower annulus 178particles of rock called gravel 180 which is of a selected screen sizelarge enough to be retained by the holes or slots 176 and to allowpassage of the oil and gas from producing zone 172 through perforations170 and slots 176 but prevent the flow of sand from the producing zone172. The shoulder 181 is connected to the mandrel 124 to locate the sealnipple 7 116 in seal bore 114 and to position tubing string 118 inproper place in the well bore.

The valve 120 has the jay-pin 126 and jay-slot 128 arranged in likemanner to the preferred embodiment to control relative movement of thehousing 122 on mandrel 124, to communicate at least one mandrel port 136to at least one housing port 130 when the housing 122 and mandrel are inone axial position and to prevent communication between the ports 130and 136 when the valve is in another axial position.

The valve 120, the crossover 134, the barrier 142, the tubing string 140and the associated parts serve to communicate the tubing string 118 tothe lower annulus 178 and to selectively communicate and preventcommunication from the lower tubing string 148 to the upper annulusabove the packer 112.

Referring now to FIGS. 6A and 6B, a well bore is illustrated with thewell casing 210 in place. A hydraulic set packer 212 is anchored insealing engagement with the casing 210. A tubing string 218 extends fromthe surface of the well bore and is in threaded engagement with acrossover valve assembly shown generally at 220. The crossover valveassembly has a housing 222 threadedly engaged to the tubing string 218.A mandrel 224 is disposed in a rotatable and slidable relation to thehousing 222. The axial movement and rotation of the housing 222 onmandrel 224 is controlled by jaypin 226 threadedly engaged with housing222 and cooperating with jay-slot 228 formed on the outside of mandrel224 in the same manner as the corresponding parts were described in thepreferred embodiment. The crossover valve is illustrated in the openposition com municating a port 230 in the housing with passage 236 inthe mandrel. A crossover 234 is disposed in sealing engagement withmandrel 224 and having a passage 236 in communication with a passage238. An inner tubing string 240 is connected with passage 238 incrossover 234 and extends to barrier 242 in the lower portion 244 oftubing string 218. A suitable seal 246 seals the lower end of tubingstring 240 to the lower portion 244 of the tubing. A tubular extension248 is attached to the barrier 242 to extend the passageway and tubingstring 240. The lower portion 244 of tubing string 218 has ports 250above the barrier 242. A tubing string 252 is suspended below packer212. Ports 254 and tubing string 252 are in communication with the ports250 in the tubing string lower portion 244. A seal bore 256 is providedinside tubing string 252. A seal 258 is provided in sealing engagementwith seal bore 256. The casing is perforated with a multiplicity ofperforations 270 to communicate with producing zones 272 to allow oiland/or gas or other liquids to flow into the casing 210. Tubing string252 is provided with a screen pipe 274 with small holes or slots 276. Anannulus 278 is provided between the lower tubing string 252 and screenpipe 274 inside casing 210. Particles of rock called gravel 280 which isof a selected screen size to allow passage of oil and gas and otherliquids from producing zone 272 through perforations 270 and slots 276but prevent the flow of sand from the producing zone 272.

A seal bore 214 is provided in tubular extensions 215 above the packer212. A collet 216 engages threads 217 above seal bore 214 and form a noleft turn latch". A no left turn latch has a collet and mating threadswhich threadedly engage upon axial movement with no rotation and releaseupon right-hand rotation of collet 216 in left-hand thread 217. Flexiblerubber 8 discs 241 are disposed on connection 243 and engage the insideof casing 210 to support sand and prevent settling of sand around theoutside of tubular extension 215 and on top of packer 212.

Referring now to FIG. 7, the arrangement for setting the hydraulicpacker is described. The hydraulic packer can be of the type generallydescribed in US. Pat. No. 3,209,831. Tubular extension 215 isillustrated with seal bore 214. Annular passage 239 is formed internallyof tubular extension 282 and externally of tubing string 240. Annulus239 is in communication with tubing string 218 through passageway 237through crossover valve 220. Sleeve 284 is in sealing engagement withtubular extension 282 with seal 286. Sleeve 284 is sealed to tubing 240with the seal means or seal sleeve 288 having an external seal 289 insealing engagement with sleeve 284 and seal ring 290. Seal sleeve 288 issupported against downward movement against shoulder 291 provided on aportion of tubing string 240. Passage 292 communicates annulus 239 toanother annulus 293 external of tubular extension 282 and internal oftubular member 215. This annulus is in communication with the inside ofpacker 212 where application of hydraulic pressure and from tubing 218will exert a pressure differential from inside packer 212 to theexterior of the packer 212. This pressure differential causes the packer212 to seal and grip the casing as described briefly hereinafter, but ismore fully described in US. Pat. No. 3,209,831.

OPERATION OF THE ALTERNATE EMBODIMENTS The alternate embodiment shown inFIG. 5 is installed in the well by installing the packer 112 in sealingengagement with the casing at the proper depth, suspending the tubingstring 152 so that screen pipe 174 has the slots or holes atapproximately the same depth as the perforations 170 in the casing 110.The tubing 148 is suspended on a hanger 149 inside the lower portion 144of tubing string 118 and is threadedly engaged to the seal nipple 158and the collet 160. The crossover 134 is threadedly engaged to the lowerportion 144 of tubing string 1 18 which is in turn threadedly connectedto seal nipple 116 to the shoulder 181 and the crossover valve 120. Thisassembly is lowered in the well casing on the tubing string 118 untilthe seal nipple 116 engages the seal bore 114. The seal nipple 158engages the seal bore 156 and the shoulder 181 engages the packer 112 tolocate the assembly in proper position.

Further operations of the alternate embodiment as shown in FIG. 5 arecarried out in the same manner as the operations with the preferredembodiment shown in FIG. 1.

Fluid flow down tubing string 118 goes down through tubing stringthrough passages 138 and 150 and port 154 into the lower annulus 178.Fluid may then flow down the lower annulus to the perforations and theholes or slots 176 in the screen pipe 174. Fluid flow returning to thesurface of the well bore can pass inwardly of the screen pipe 174through holes or slots 176 into the bottom of tubing string 148 upthrough the tubing string 148 upwardly through the passage 137 andupward inside lower portion 144 of tubing string 118 external of tubingstring 140 and through ports 136 and 130 into the annulus above thepacker where the fluid may be conducted upwardly to the surface of thewell bore.

Referring now to FIGS. 6A and 6B, this alternate embodiment utilizes ahydraulic set packer and provides an installation which is completelyretrievable. All of the apparatus is assembled and lowered into the wellbore on the tubing string 218 until the slots 276 and the screen pipe274 are substantially at the same depth as casing perforations 270. Thehydraulic packer is set by exerting hydraulic pressure inside the tubingstring 218. Seal sleeve 284 is in sealing engagement in annularpassageway 239 as hereinbefore described. The setting pressure exerteddown tubing string 218 is communicating through passage 292 and annularpassageway 293 to the interior of the packer 212. This pressuredifferential causes the packer 212 to seal and grip the casing bycausing piston slips 294 to expand to grip the casing 210. Hydrauliccylinder 295 is responsive to the described pressure differential tocompress packing elements 296 into sealing engagement with the casing.The downward thrust from a cylinder 295 is supported by slips 297 whichare expanded into gripping engagement with the casing 210 by taperedexpander 298. Mechanical locking devices 299 and 300 hold the hydraulicpacker in set position.

Setting pressure exerted down tubing string 218 to accomplish thesetting of hydraulic packer 212 is sealed by seal sleeve 284 which issupported in sealing position by frangible shear screws 301. Thesefrangible parts have a predetermined strength to support a predeterminedpressure differential from tubing string 218.

Application of sufficient pressure to shear screws 301 removes supportfor sleeve 284 in the position shown in FIG. 7 and the pressure causessleeve 284 to move downwardly to the position shown in FIG. 6A so thatcommunication from annulus 239 is established external of tubing string240 to ports 250 and 254.

After the hydraulic set packer 212 is anchored in sealing engagement tothe well casing 210, the well treating and gravel packing operations canbe carried out as hereinbefore described using the crossover valve 220.After gravel 280 has been placed in the annulus 278, the tubing string218 and crossover valve assembly 220 and seal nipple 213 can be releasedfrom the tubular extension 215 and seal bore 214 to permit retrieval ofthe tubing string 218, crossover valve 220 and the associated equipmentleaving the packer 212, the lower tubing string 252 and the screen pipe274 in place.

If it is desired to retrieve the packer 212 and the remainder of theequipment in the well, the gravel can be circulated back in a reversemanner from the method by which it was positioned by opening crossovervalve 220 and pumping fluid down the upper casing annulus above thepacker to enter housing port 230, through crossover passage 236 and downtubing string 240, out the screen pipe slots 276 to pick up the gravel280 and return it up through ports 254 and 250, up through the annulusexternal to tubing string 244 and passage 237, and upward through tubingstring 218 to the surface of the well bore. After a substantial portionof the gravel has been removed, the entire apparatus may be retrieved bylifting upwardly with tubing string 218 to rlease the hydraulic packer212 from the 10 sealing engagement with the well casing in a manner morefully described in US. Pat. No. 3,209,831. The packer 212 may bereleased from the well casing and the entire apparatus may be retrieved.

It should thus be appreciated that there has been described andillustrated herein the preferred embodiments of the invention. However,various modifications of these embodiments will occur to those skilledin the art. For example, the invention contemplates that those skilledin the art may desire to first acidize or otherwise treat the well andthen gravel pack the formation of interest. The invention alsocontemplates the gravel packing of the formation and then the furthertreatment of the well. Likewise, the invention contemplates that thegravel packing material may be recovered from the well at any time sodesired.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

1. A crossover valve apparatus adapted for use in a well bore having afirst tubing string and a second tubing string inside a portion of thefirst tubing string comprising:

a housing having a first seal bore,

a second seal bore spaced axially from said first seal bore,

at least one lateral opening located between said first and said secondseal bores;

a tubular mandrel in said housing and movable axially from a firstposition to a second position in said housing and rotatable in saidhousing and having a first seal engaging said first seal bore in bothsaid first and said second positions, a third seal spaced axially fromsaid first seal and engaging said second seal bore in said secondposition, a second seal located between said first seal and said thirdseal, and engaging said second seal bore in said second position, and atleast one side port located between said second seal and said thirdseal, and communicating with said at least one lateral opening in saidfirst position; and releasable means for locking said mandrel and saidhousing in one of said first or second positions, and

for permitting said mandrel and said housing to move to the other ofsaid first or second positions.

2. Apparatus according to claim 1 wherein said releasable means lockssaid mandrel and said housing in said first position.

3. Apparatus according to claim 2 wherein said releasable means comprisea jay-slot and cooperating jay-slot pin.

4. Apparatus according to claim 3 wherein said jayslot aligns saidjay-slot pin in locking position in said jay-slot upon axial movement ofsaid mandrel and said housing to said first position.

1. A crossover valve apparatus adapted for use in a well bore having afirst tubing string and a second tubing string inside a portion of thefirst tubing string comprising: a housing having a first seal bore, asecond seal bore spaced axially from said first seal bore, at least onelateral opening located between said first and said second seal bores; atubular mandrel in said housing and movable axially from a firstposition to a second position in said housing and rotatable in saidhousing and having a first seal engaging said first seal bore in bothsaid first and said second positions, a third seal spaced axially fromsaid first seal and engaging said second seal bore in said secondposition, a second seal located between said first seal and said thirdseal, and engaging said second seal bore in said second position, and atleast one side port located between said second seal and said thirdseal, and communicating with said at least one lateral opening in saidfirst position; and releasable means for locking said mandrel and saidhousing in one of said first or second positions, and for permittingsaid mandrel and said housing to move to the other of said first orsecond positions.
 2. Apparatus according to claim 1 wherein saidreleasable means locks said mandrel and said housing in said firstposition.
 3. Apparatus according to claim 2 wherein said releasablemeans comprise a jay-slot and cooperating jay-slot pin.
 4. Apparatusaccording to claim 3 wherein said jay-slot aligns said jay-slot pin inlocking position in said jay-slot upon axial movement of said mandreland said housing to said first position.